Transaxle oil cooler pumps Options

[pcar916]

How many of you are using gear pumps instead of diaphragm types and what filter element (micron) sizes are you using?

[pcar916]

I didn't give Patrick a call because I already have a lot of this stuff around now that I've been stockpiling over the last year or so. I'll just have to buy a little more hose, some more hose fittings and a few adapters. Then fab up the catch can and fittings for that circuit.

The controller is a pulse-width unit. Simple, reliable, and I don't have to throw off as much heat as a rheostat would. I figured I'd wire it in so that if I get too much cooling (return oil <160F) I can simply slow down the pump speed rather than break open the cooler ducting to blank-off some of it. If I always run the pump at full-bore I'll install a switch and use the controller for something else, like pushing the cockpit heat from my front oil cooler in the winter time. I use a 4 in bilge fan on my front heater system too. Good value that.

I am going to install the pump motor in moving air as it doesn't have it's own fan. Whether that turns out to be in the wheel well or upstream of the cooler fan housing I don't know yet. The specs on the pump read that it's top operating temp should be 150F.

Since the oil going through it will be hotter than that, there will be heat conducted from the pump housing into at least the output bearing and the lower half of the motor. Maybe that's overkill but I'm starting with a clean slate so it's easy to avoid that potential problem.

The reason for the valve was to avoid letting the pump lose it's prime. Even though it's self priming it makes me feel better. As to the extra oil, I thought it would be a potential leakage problem (i.e. output flange seals) if a lot of oil went back into the case.